Golf club

ABSTRACT

The invention relates to a golf club ( 1 ) comprising a shaft ( 3 ) provided with a handle portion ( 2 ) and a club blade ( 5 ) projecting from the lower portion ( 4 ) of said shaft ( 3 ), the hitting surface ( 6 ) of said blade is provided with a plurality of scores or grooves ( 7 ). Those grooves ( 7 ) are arranged at a predetermined mutual distance and do extend in a diverging or parallel pattern or area over at least the hitting surface ( 6 ) of the club blade ( 5 ).

[0001] The present invention relates to a golf club which comprises ashaft, provided with a handle portion, and a club blade projecting fromthe lower portion of the shaft, a plurality of depressions or groovesextending across the hitting surface of the blade.

[0002] The golf clubs which today are available in the market do,practially all of them, on the hitting surface on the club blade exhibitsome form of patterns or grooves, the primary purpose of which is toincrease the friction and accordingly also inter alia the ball backspingenerated in the hitting moment between the club blade and the golfball. In those cases when a golf ball is hit exactly in the correctpoint on a standard club blade and with a correct force, which can neverbe guaranteed, the golf ball travels to the intended spot and the playercan use any standard club to reach a completely satisfactory result. If,however, when a conventional standard club hits the ball above the idealhit point the ball will travel a shorter distance than intended due tothe fact that this portion of the blade moves slower than the centralpoint because in that case the radius of the rotation circle of the clubblade is shorter. The opposite will occur when the ball hits a standardblade at its lower part meaning that in this case the ball will travelfarther than desired because the radius of the rotational circle of theclub blade will be greater. The difference in terms of speed between theupper and the lower point on the blade amounts to a number ofsignificant percent values.. In addition thereto attention has to bepaid to the fact that when a stroke is made and the lower portion of theblade hits the ball the blade will move at the higher speed, also due tothe fact that in this case the blade cuts less or not at all down in theground. When this occurs there will be generated a certain resistancewhich reduces the speed. On the other hand, if the upper portion of theblade hits the ball, the soil will always present a resistance becausethe blade does then dig itself deeper down than ideal. Irrespective ofhow the club blade hits the ball the latter is all the time at the samedistance from the solid support layer. The perfect stroke, a so called“square hit” does not exist in reality because the movement of the golfplayer's hips is slower than the club blade movement through the air.Consequently, a club blade moves almost exactly along the periferi ofits rotational circle in response to a stroke and, for this reason, theball travelling distance will be different in response to the locationof the golf ball hitting point on a standard blade.

[0003] The object of the present invention is to provide a golf club ofthe type mentioned above which comprises a club blade having grooves onits hitting surface, said grooves being oriented in such a way that theproblems existing in the prior art golf club have been eliminated. Thecharacteristic features of the invention are set out in the patentclaims.

[0004] Thanks to the invention there has now been provided a golf clubwhich in an excellent manner satisfies the demands and, in additionthereto, can be manufactured in a convenient way. Accordingly, asdistinct from the golf clubs of today, a club according to the presentinvention offers a automatic compensation of “bad” hits. Stated in otherwords, the ball will always stop in desired positions irrespective ofwhether it has been hit at a high or a low level, at the toe which movesquicker than the heel or at the heel or in some other spot. This resultis achieved thanks to the fact that the grooves are arranged at apredetermined distance between themselves so that they generatedifferent friction forces and/or in the way that the grooves exhibit adiverging or parallel extension over at least the hitting surface of theclub blade. It is also possible, by variation of the spacing between thegrooves, when the stroke is made to create different “backspins”. Thedesign of the blade according to the invention does also involve thatthat irrespective of the ball hitting point on the blade the trajectoryof the ball will always be correct including its movement through theair and its rolling along the ground until it has stopped. Stated inother words, a long air passage yields a large backspin effect and ashort air passage yields a small backspin effect. The final result isthat the ball will always stop in the correct position, the desireddistance which could be expected from a certain club.

[0005] Some preferred embodiments of the invention will now bedescribed, reference being made to the drawing.

[0006]FIG. 1 illustrates a club blade having diverging grooves runningfrom the toe to the heel of the club blade,

[0007]FIG. 2 shows a club blade having diverging grooves which aredisplaced in respect of their relative positions as extending over thehitting surface of the club blade,

[0008]FIG. 3 shows an alternative embodiment illustrating a club bladeat which the grooves are diverging and located in the hitting surface ofthe blade, the distance between them being smaller lower down thanhigher up. The grooves diverge from the toe towards the heel,

[0009]FIG. 4 shows a club blade having parallel grooves with aninterdistance between them which is smaller at the lower portion of thehitting surface than at the upper portion,

[0010]FIG. 5 does diagrammatically illustrate the rotation circle of aclub blade upon the stroke and different hitting points on the blade atdifferent radii,

[0011]FIG. 6 is a diagrammatical view showing different travellingdistances of a golf ball in response to which portion of the blade thathits the ball and to how the ball moves on the ground after the strokewhich in the second case is somewhat stronger than in the first case,

[0012]FIG. 7 does diagrammatically illustrate the type of back backspinrotation performed by a ball when a club blade according to theinvention is used and in response to the hitting position on the bladeand the lateral spreading determined by whether the hit takes place highup or lower down on the blade,

[0013]FIG. 8 does diagrammatically show different ball travellingdistances, where a) refers to a perfect stroke—perfect speed, b) toohigh speed with a hitting position low down on the blade and intensivebackspin, and c) low speed—hitting position high up on the blade—smallbackspin.

[0014] As appears from the drawings they do show a golf club 1comprising a shaft 3 provided with a handle portion 2 and a club blade 5projecting from the lower portion 4 of shaft 3. Extending over thehitting surface 6 is a plurality of depressions or grooves 7 located atpredetermined interspacings and exhibiting a diverging or parallelpattern over the surface 6 of club blade 5. The width and thecross-sectional profile of grooves 7 are the same in all the embodimentsillustrated, along all of the hitting surface 6 and also in thelongitudinal direction of grooves 7. According to the invention thehitting surface 6 of club blade 5 may exhibit a plurality of grooves 7,the distances between them being different at the foot and at the top ofthe blade 5 of club 1. The grooves 7 can diverge in one direction fromthe toe 8 of the club blade 5 to the heel 9 of the club blade 5.Alternatively, grooves 7 may extend from the heel 9 towards the toe 8 orat other imaginable angles. Grooves 7 may also as an alternative divergefrom the foot to the top or the other way around. Stated in other wordsgrooves 7 may converge and/or diverge at all imaginable angles anddirections. FIG. 2 illustrates combinations of various grooves 7positioned in other patterns than those mentioned above, the groovesbeing displaced relatively each other in their diverging longitudinaldirection.

[0015] Another alternative embodiment has been shown in FIG. 3 where thegrooves 7 diverge from the toe 8 towards the heel 9, the grooves 7 alsobeing closer to each other at the foot than at the top of club blade 5.

[0016] Thanks to the positioning according to the invention of thegrooves 7 with different distances between them at the foot and at thetop, as shown in FIGS. 3 and 4, there has been created a possibility tovary the backspin in response to whether a golf ball 10 hits at the topor at the foot. Different backspins means that the ball 10 will roll, ortends to roll, different distances backwards on the ground with which itcomes into contact following its passage through the air. An arrangementof grooves 7 closer to each other on the club blade 5 creates morebackspin and, accordingly, ball 10 will pass somewhat too long throughthe air after having been hit by the lower portion 11 of blade 5performing a quicker movement than the upper portion 12 and, as shownfor example in FIG. 5, still travel a approximately correct distanceand, when the grooves 7 are less close to each other less backspin willbe generated meaning that the ball 10 also in that case travels thecorrect distance. Consequently, thanks to the invention one cancompensate the stroke distance to a correct value, corresponding to thatthe ball 10 is hit by the centre portion 13 irrespective of whether itdoes actually hit the top or the foot of blade 5. The same function isachieved disregarding whether ball 10 hits the toe 8 of blade 5 or itsheel 9. Contact at the toe 8 gives the ball 10 a higher spin than atheel 9, meaning that the grooves 7 should then be located closer at thetoe 8 than at the heel 9 resulting in that a hit at the toe 8 causesmore backspin than a hit at heel 9. The divergence of grooves 7 at theheel 9 compensates the total length of the movement including the airtravel and the ground rolling irrespective of whether ball 10 is hit byblade 5 at the toe 8 thereof or at the heel 9, the wanted correctdistance being always achieved.

[0017] Consequently, as has been mentioned above, the contact point onthe club blade 5 with the ball 10 will always yield a correct travellingdistance of ball 10 up to the moment when it is lying still on theground after having finished its air travel and the rolling.

[0018] In the case when the club blade 5 hits the ball 10 to high itdoes actually do so to late. The result of this will be that the ball 10will deviate to the left for a right-handed player and to the right fora left-handed player. If the ball 10 hits the blade 5 too low this meansat the blade 5 hits the ball 10 too early and the ball 10 will then in alogical manner deviate to the right if the player is right-handed. Theexplanation of this becomes obvious if one, for each of the differenthitting points, places any imagined vertical plane at the right anglesto the stroke direction. When the ball 10 is hit by the centre of blade5 the direction will be correct but all other hitting points will causea greater or smaller incorrect direction. The spread in the lateraldirection can amount to as much as 7-8 metres after an air travel withour without a rolling distance, for example 175 m. The characteristicfeature of the invention, diverging grooves 7, means that the backspinrotation of ball 10 will vary in response to the actual hitting point ofball 10 on club blade 5. This has been illustrated more in detail inFIGS. 5 and 6. A hitting point at the centre of blade 5, which also isthe ideal point, yields a “straight” backspin. If the ball 10 is hit bythe blade 5 to high up, the result will, due to the presence of thediverging grooves 7, become a screwed backspin causing the ball 10 torotate to the right. Since, at a hit too high up, the vertical planementioned above causes the ball 10 in a normal manner to deviate to theleft and the ball 10 now is in a rotation movement to the right, thosetwo parametres will cancel each other and, finally, the ball 10 willstop at the wanted spot, namely correctly in the desired strokedirection. Conversely, if the ball 10 is hit by the blade 5 too low, itwill be given it a backspin directed to the left. This does in its turncompensate away the lateral error which otherwise would have caused theball 10 to travel too far to the right. It can consequently be said thatirrespective of where on the blade 5 it contacts the ball 10 thediverging or parallel grooves 7 will compensate away all erroneous hitsand the ball 10 will always reach the wanted spot. Moreover, after itsair travel ball 10 will roll on the ground in its screwed backspin tothe right or to the left, respectively, and still more compensate alateral error so that the ball 10, when eventually resting still on theground, will be found in the wanted position.

[0019] Accordingly, the final result will be that thanks to the conceptaccording to the invention the ball 10 will reach the correct spot inboth the longitudinal and the lateral direction and this irrespective ofwhether the club hits the ball 10 correctly, to the left, to the right,at the top or at the foot, too early or too late. This is not the caseat the golf clubs today available in the market. The old concept,featuring parallel grooves with the same spacing, does accordingly notoffer any compensation for bad hits be it in the longitudinal or in thelateral direction. The final position of a ball after its air travel andthe rolling on the ground can thus be controlled both longitudinally andlaterally in an optimal way when a golf club according to the inventionis in use.

1. A golf club comprising a shaft (3) provided with a handle portion (2)and a club blade (5) projecting from its lower portion (4) and, on thehitting surface (6) of the blade (5), a plurality of scores or grooves(7), which are located at a predetermined distance from each other andover at least the hitting surface (6) of the club blade (5) are arrangedin a diverging or parallel pattern, characterized in that said grooves(7) on the hitting surface (6) of the club blade (5) are at differentmutual distances, as counted from the blade bottom to its top or fromits toe (8) to its heel (9), or in the opposite direction, and do at thesame time diverge from the toe (8) towards the heel (9) or from thebottom towards the top.
 2. A golf club as claimed in claim 1,characterized in that said grooves (7) are arranged at a smaller mutualdistance at the bottom than at the top of the club blade (5).
 3. A golfclub as claimed in claim 1, characterized in that the distances betweensaid grooves (7) are selected so as to match the wanted backspin effect.4. A golf club as claimed in claim 1, characterized in that thedistances between said grooves (7) vary in relation to the distance fromthe centre of a club blade (5) towards the grooves (7).
 5. A golf clubas claimed in claim 1, characterized in that said grooves (7) arediverging and also arranged over the hitting surface (6) of the clubblade (5) at varying mutual distances.
 6. A golf club as claimed inclaim 1, characterized in that the extension of each groove (7) over thehitting surface (6) of the club blade (5) is displaced relatively anadjacent groove (7).
 7. A golf club as claimed in claim 1, characterizedin that said grooves (7) extend continously and/or discontinously overthe hitting surface (6) of the club blade (5).